Conventional multi-phase power supplies may include one or more DC to DC converters to produce a respective output voltage to power a load. Any number of phases in a multi-phase power supply can be operated in parallel to produce the output voltage powering the load.
One type of DC-to-DC converter is a single-stage power converter system. As its name suggests, in the single-stage power converter system, each phase includes a single power converter to convert an input voltage such as 12 V DC (Volts Direct Current) into a respective target output voltage such as 1 volt DC to power a load.
A so-called Constant ON Time (COT) buck switching regulator has fixed pulse-width modulator on-time and uses off-time Pulse Width Modulation (PWM) to regulate an output voltage.
As is well know, the switching mechanism in a switching power supply introduces a ripple voltage in the output voltage feedback sense point due to the equivalent series resistance (ESR) in a respective output capacitor. The output voltage of buck regulator is regulated based on the ripple in the output and feedback voltage. In many applications, it is desirable to minimize the ripple in the output voltage. However, this can result in too little ripple amplitude to achieve jitter free PWM. Jitter reduces efficiency and can lead to system instability.
In certain conventional power supply systems, an artificial ramp is used to compensate for low ripple solutions.